Class BoundedPriorityQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

org.openjdk.jmh.util.BoundedPriorityQueue<E>

Type Parameters:

E - type of the element

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, Queue<E>

public class BoundedPriorityQueue<E>
extends AbstractQueue<E>
implements Serializable

Bounded variant of PriorityQueue. Note: elements are returned in reverse order. For instance, if "top N smallest elements" are required, use new BoundedPriorityQueue(N), and the elements would be returned in largest to smallest order.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private final Comparator<? super E>	comparator
private final int	maxSize
private final Queue<E>	queue
private static final long	serialVersionUID

Constructor Summary

Constructors

Constructor	Description
BoundedPriorityQueue(int maxSize)	Creates a bounded priority queue with the specified maximum size and default ordering.
BoundedPriorityQueue(int maxSize, Comparator<? super E> comparator)	Creates a bounded priority queue with the specified maximum size.

Method Summary

Modifier and Type	Method	Description
boolean	add(E e)
Iterator<E>	iterator()
boolean	offer(E e)
E	peek()
E	poll()
private static <E> Comparator<? super E>	reverse(Comparator<? super E> comparator)	Internal queue should be in fact in reverse order.
int	size()

Methods inherited from class AbstractQueue

addAll, clear, element, remove

Methods inherited from class AbstractCollection

contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface Collection

contains, containsAll, equals, hashCode, isEmpty, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray, toArray

Methods inherited from interface Iterable

forEach

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

maxSize

private final int maxSize

comparator

private final Comparator<? super E> comparator

queue

private final Queue<E> queue

Constructor Details

BoundedPriorityQueue

public BoundedPriorityQueue(int maxSize)

Creates a bounded priority queue with the specified maximum size and default ordering. At most maxSize smallest elements would be kept in the queue.

Parameters:

maxSize - maximum size of the queue

BoundedPriorityQueue

public BoundedPriorityQueue(int maxSize,
 Comparator<? super E> comparator)

Creates a bounded priority queue with the specified maximum size. At most maxSize smallest elements would be kept in the queue.

Parameters:

maxSize - maximum size of the queue

comparator - comparator that orders the elements

Method Details

reverse

private static <E> Comparator<? super E> reverse(Comparator<? super E> comparator)

Internal queue should be in fact in reverse order. By default, the queue aims for "top N smallest elements". So peek() should return the biggest element, so it can be removed when adding smaller element

Type Parameters:

E - type of the element

Parameters:

comparator - comparator that designates ordering of the entries or null for default ordering

Returns:

reverse comparator

add

public boolean add(E e)

Specified by:

add in interface Collection<E>

Specified by:

add in interface Queue<E>

Overrides:

add in class AbstractQueue<E>

offer

public boolean offer(E e)

Specified by:

offer in interface Queue<E>

poll

public E poll()

Specified by:

poll in interface Queue<E>

peek

public E peek()

Specified by:

peek in interface Queue<E>

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in class AbstractCollection<E>

size

public int size()

Specified by:

size in interface Collection<E>

Specified by:

size in class AbstractCollection<E>